Quote:
Originally Posted by dataway
Density worked. Took some measurements, did some weighing .. all my materials came out to the expected products within about 1% error.
Lots of UHMW as expected, some PTFE, and couple of 1/2" thick 4" wide, 18" long sheets of Delrin, and one nice 12" x 6" x 1/2" sheet of Ketron Peek. Surprised, about $1000 worth of exotic plastics (at McMaster prices) .... most of that stuff came from people that donated it cause they know I make a lot of projects, or scrap that I picked up at auctions.
Already laminated the density chart to go in my shop info binder 
Shame the Delrin is in 1/2" sheets, would be a pain to machine into bushing. |
Good work! Glad it helped you sort your stuff.
Which way are you leaning?
IMO, any of those would probably work fine but I'd go with stronger/tougher because of the probable dirt and dust.
Delrin is a standard "go-to" for bearing surfaces but you were concerned about temperature. I think it would be OK personally but the PTFE and PEEK will definitely be more heat-proof. The PTFE is super slippery, inert, and temp-stable but I'm not sure how it would behave coated with sand.
The PEEK is high-tech. I'll bet it was expensive! It probably would be best for a bearing if carbon- or even PTFE-filled but even unfilled PEEK should be "slippery enough" for your bushing. PEEK may "out-wear" the other options if dirt is present as it is super tough. PPS is a similar material and I remember it being VERY wear resistant.
Thanks for sharing this latest project.
Mike